Posted on by Karl

LuaInterface

While having a beer with an old friend yesterday, we started discussing the use of scripting languages in applications. Having seen a number of .net applications with embedded Lua scripting engines, I suggested that he look at LuaInterface, with the disclaimer that I hadn’t used it much myself.

Having nothing better to do this afternoon, I decided to download the whole thing again (the last version I’d downloaded had languishing in my download folder for about 10 months, and was probably out of date, if I could find it in the first place) and have a go at it. Attached are the results of my messing around. It’s by no means a best practice guide – or even a good practice guide, for that matter – but it looks like it’s working.

Getting lua to work in .net is simple enough; add a reference to luainterface.dll and put the luanet and lua51 dlls somewhere accessible to your application. In my case I added them as content in my VS project, and set the copy mode to “Copy Always”.

To initialise a scripting context, create a new instance of LuaInterface.Lua, which is as simple as:

LuaInterface.Lua m_ScriptingEngine = new LuaInterface.Lua();

To expose a .net object to the scripting engine, use the engine’s indexer, like so:

ScriptingEngine[“winform”] = this;

this allows the scripts to access the object and it’s properties as follows:

winform.Text = “Title Goes Here”

The lua syntax to call a method from a script is <object>:<method>(parameters) –

winform:Close()

The scripts can also access and create .net types, such as forms and buttons. The assemblies and the types must be registered first, as follows:

— Reference the .Net assemblies.
luanet.load_assembly(“System.Windows.Forms”)

— Import the specific types.
Menu = luanet.import_type(“System.Windows.Forms.MainMenu”)
MenuItem = luanet.import_type(“System.Windows.Forms.MenuItem”)

I’ve uploaded my example project. Nothing groundbreaking, but it may be useful for anyone who’s still testing the waters on this.

Further reference

Lua Reference Manual
Lua Home

9 Replies to “LuaInterface”

  4. Thank you for your comments 🙂

    To call Lua functions from your C# application, you will need to get the function from the instance of the scripting engine and use its Call method i.e.

    Lua instance = new Lua();
    …
    …
    LuaFunction myFunction = instance.GetFunction(“myLuaFunction”);
    myFunction.Call();

    Hope this helps!

  6. I would like to get your example project working. Unfortunately it fails using Visual Studio 2012 on 64bit Windows 7. I already tried replacing LuaInterface with the current version but it did not help. Did you every try to compile it again under a newer version of Visual Studio?

    LuaInterface seems to be really a great tool – unfortunately it seems nobody is using it and there is almost no documentation – so for me it is really hard to get started. Your example seems to be structured very clearly so I was hoping to use it as a starting point.

    1. Thank you for your comment, Michael. Unfortunately I haven’t done any .Net development in some time, so can’t be of much help on this subject – have you tried asking on the Lua users mailing list? http://lua-users.org/

  7. Ok, no Problem, thanks for your answer! I have ask already on the lua mailing list but now I think that it is more a .net problem than a lua problem. So I will probably have to ask in a .net forum.

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